ORIGINAL: jcchartboy
Eldequello,
I am not one to usually question your wisdom, however according the article I quoted above,(based on Remmingtons own statements), your statement concerning the
reason for the .280 being loaded down is not technically correct.
As you seem very interested in these types of matters I would like hear your thoughts on this matter...
Several years ago I became intrigued by this chapter in the .280’s history and checked out the “loaded down” rumor with a few of the older heads at Remington. As with many rumors from the shooting industry, there’s a grain of truth to this one, but the real facts I gleaned tell us a lot more
Unlike earlier autoloaders such as Remington’s M81, which were limited to mild cartridges such as the .30 and .35 Remington, the M740, which was introduced in 1955, was designed for rip-snorting calibers such as the .30/06. It was a successful rifle and would have been even more so had it been chambered for the .270 Winchester, but it wasn’t. And the word going around at the time was that the M740 couldn’t handle the 270’s pressures. And here’s where the strange saga of the .280 gets particularly interesting.
Not counting some of Remington’s interoffice politics, personal opinions and jealousies regarding the .270 during the 1950s, I learned that the M740 and .270 actually did not make a good match. Not necessarily because of the .270’s high pressures, but because the M740 tended to be finicky about what it was fed, its gas-operated system being reliable only when adjusted to rather specific pressure levels.
The .270 loads of the day, I was told, tended to develop varying pressure levels, which in turn could have resulted in the M740’s erratic operation. Thus the .280 was not so much “loaded down” as loaded to specific pressures compatible with the M740. Apparently, it isn’t often noticed that the M740 was also chambered for Remington’s new .244, a hot round that, like the .270, generated pressures over 50,000 PSI. In 1960, when the M742 replaced the M740, it too was catalogued sans the .270.
Basically according to this authority, the .280 was not in fact "loaded down" to work in the autoloaders because the autoloaders "cannot stand", the pressure. In reality the autoloaders could have withstood
more pressure. However, their operation was dependent upon a specific pressure, and that pressure was lower than the standard pressure produced by a "normally" loaded .280 shell.Therefore it was not in fact a safety issue, only a matter of functionality...
Any thoughts?
Yes. My answer concerning pressure actually was an oversimplified explanation. It is true that the M740, and all succeeding Remington autoloaders based on that design, are certainly strong enough to handle the maximum pressure level of any round in the .30/'06 stable, but as that article notes, the 740 types are "finicky". Actually, the situation was that
maximum performance levels in both the .270 Win. and .280 Remington are dependent on large volumes of slow-burning powders like H4831, RE 22, etc., which, although producing peak presures well within the design limits of the rifles, result in
pressures at the gas port which are too high. This makes the action open sooner, and with more energy and velocity, than the cartridge cases can often stand. IF the action opens too soon, before pressures have dropped enough, the cartridge case is still clinging to the chamber walls while the extractor is trying to snatch it out of the chamber! NOT GOOD!!
This can result in broken extractors or cartridgesthat have the headstorn off, leaving the rest of the case still in the chamber. Although this damages neither the rifle or the shooter, either occurrance can result in a stoppage at the wrong time. (I have actually seena case head torn off bya Model 742 in .30/'06 which was loaded with a 200-grain bullet and a maximum charge of RE 22. I don't recall the exact amount 0f RE 22. But there was no damage to the gun, just thehead ripped off the case!!)
In other words, the "finicky" description refers to the fact that gas port pressures in the 740-series rifles has to be very closeto a specific level for functional reliability and to prevent damage.
Thisis comparable to the situation with the M1 Garand, in which slow-burning powders and/or too-heavy bullets can cause operating rod damage due to pressures being too high at the gas port.
So, perhaps maximum peak pressures in the early .280 factory ammo were not below those of say, the .270 Win. But medium burning rather than very slow burning powders were used to make sure the pressure had dropped enough by the time the bullet passed the gas port. Note this has a cumulative effect on the maximum attainable muzzle velocities in calibers like the .270 and .280 as well,which is alot likeactually down-loading the ammo to begin with.
I am guilty of stating this in an oversimplified way, and your comments are indeed correct.